mutable_cell.hpp

/*
 * live_cells_cpp
 * Copyright (C) 2024  Alexander Gutev <alex.gutev@gmail.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you
 * may not use this file except in compliance with the License.  You
 * may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 * implied.  See the License for the specific language governing
 * permissions and limitations under the License.
 */
 
#ifndef LIVE_CELLS_MUTABLE_CELL_HPP
#define LIVE_CELLS_MUTABLE_CELL_HPP
 
#include <memory>
 
#include "cell_state.hpp"
#include "stateful_cell.hpp"
#include "tracker.hpp"
 
namespace live_cells {
 
    class batch_update {
    public:
        batch_update();
        ~batch_update();
 
        batch_update(const batch_update &) = delete;
        batch_update& operator=(const batch_update &) = delete;
 
    private:
        bool is_batching;
 
        static bool is_batch_update();
 
        static void add_to_batch(std::shared_ptr<cell_state> state);
 
        template <typename T>
        friend class mutable_cell_state;
    };
 
    template<typename T>
    class mutable_cell_state : public cell_state {
    public:
        using cell_state::cell_state;
 
        mutable_cell_state(key_ref key, T value) :
            cell_state(key),
            value_(value) {
        }
 
        T value() {
            return value_;
        }
 
        void value(T value) {
            if (value_ != value) {
                notify_will_update();
                value_ = std::move(value);
 
                if (!batch_update::is_batch_update()) {
                    notify_update();
                }
                else {
                    batch_update::add_to_batch(this->shared_from_this());
                }
            }
        }
 
    protected:
        void silent_set(T value) {
            value_ = std::move(value);
        }
 
        static bool is_batch_update() {
            return batch_update::is_batch_update();
        }
 
        void add_to_batch() {
            batch_update::add_to_batch(this->shared_from_this());
        }
 
    private:
        T value_;
    };
 
    template<typename T>
    class mutable_cell : public stateful_cell<mutable_cell_state<T>> {
        typedef stateful_cell<mutable_cell_state<T>> parent;
 
    public:
        typedef T value_type;
 
        mutable_cell() : parent(key_ref::create<unique_key>()) {}
 
        mutable_cell(T value) :
            mutable_cell(key_ref::create<unique_key>(), value) {}
 
        mutable_cell(key_ref key, T value) :
            parent(key, value) {
        }
 
 
        T operator=(const T &value) {
            this->value(value);
            return value;
        }
 
        T operator=(const T &value) const {
            this->value(value);
            return value;
        }
 
        T value() const {
            return this->state->value();
        }
 
        void value(T value) const {
            this->state->value(value);
        }
 
        T operator()() const {
            argument_tracker::global().track_argument(*this);
            return value();
        }
    };
 
    template<typename T>
    mutable_cell<T> variable(T value) {
        return mutable_cell<T>(value);
    }
 
    template<typename T>
    mutable_cell<T> variable(key_ref key, T value) {
        return mutable_cell<T>(key, value);
    }
 
    template<typename F>
    void batch(F fn) {
        batch_update b;
        fn();
    }
 
    template <typename T>
    T operator+=(const MutableCell auto &c, const T &value) {
        return c = c.value() + value;
    }
 
    template <typename T>
    T operator-=(const MutableCell auto &c, const T &value) {
        return c = c.value() - value;
    }
 
    template <typename T>
    T operator*=(const MutableCell auto &c, const T &value) {
        return c = c.value() * value;
    }
 
    template <typename T>
    T operator/=(const MutableCell auto &c, const T &value) {
        return c = c.value() / value;
    }
 
    template <typename T>
    T operator%=(const MutableCell auto &c, const T &value) {
        return c = c.value() % value;
    }
 
    template <typename T>
    T operator<<=(const MutableCell auto &c, const T &value) {
        return c = c.value() << value;
    }
 
    template <typename T>
    T operator>>=(const MutableCell auto &c, const T &value) {
        return c = c.value() >> value;
    }
 
    template <typename T>
    T operator&=(const MutableCell auto &c, const T &value) {
        return c = c.value() & value;
    }
 
    template <typename T>
    T operator^=(const MutableCell auto &c, const T &value) {
        return c = c.value() ^ value;
    }
 
    template <typename T>
    T operator|=(const MutableCell auto &c, const T &value) {
        return c = c.value() | value;
    }
 
    auto operator++(const MutableCell auto &c) {
        auto value = c.value();
        c = ++value;
 
        return value;
    }
 
    auto operator++(const MutableCell auto &c, int) {
        auto old = c.value();
 
        ++c;
        return old;
    }
 
    auto operator--(const MutableCell auto &c) {
        auto value = c.value();
        c = --value;
 
        return value;
    }
 
    auto operator--(const MutableCell auto &c, int) {
        auto old = c.value();
 
        --c;
        return old;
    }
 
}  // live_cells
 
#endif /* LIVE_CELLS_MUTABLE_CELL_HPP */